The aim of this research is the total synthesis of the Cephalotaxus group of alkaloids, especially the harringtonines which have shown significant inhibitory action against experimental lymphoid leukemia. The harringtonines are esters of the parent alkaloid cephalotaxine, which we have already synthesized. Neither cephalotaxine nor the acid moieties show activity alone. Esterification is vital for antitumor activity. In addition we hope to synthesize the structurally related oxycephalotaxines. We hope to synthesize the unusual loline group of Pyrrolizidine alkaloids in order to investigate potential antitumor activity in this series. We wish to investigate biologically active metabolites produced by various microorganisms, and in particular intend to determine the structure of the tremorogenic toxin tremortin-A. We hope to synthesize the antitumor antibiotic sparsomycin by a route which will establish the stereochemistry of this molecule. Finally, we plan to synthesize the aglycone portions of the cancerostatic and antitumor antibiotic chromomycins, mithramycin and olivomycins. We hope the above work will lead to the development of new cancer chemotherapy agents, as well as the development of new methods of organic synthesis.